It's really price-y and I am not sure about if I could create applications for f-droid if they aren't open source and how it might go with something like remobjects.com/gold/

One of the key principles of f-droid is that it must be reproducible (I think) or open source with it being able to be built by f-droid servers but I suppose reproducibility must require having this software which is paid in this case.